Age-Related Differences Between Young and Old Adults: Effects of Advance Information on Task Switching.

In this study we investigated the effects of advance information on task switching in young and old adults, using two forms of advance information (memory-based and cue-based) and a no advance information task. We compared 19 healthy young and 19 healthy older adults in terms of their behavioral performance and neural correlates under these three task-switching paradigms. We observed a significant difference in mixing cost between the two age groups. There was no switch cost group difference on the memory-based and cue-based tasks, but older adults showed a larger switch cost than younger adults on the no advance information task. On evoked potential measures, there was no group effect in P3 cue-locked positivity; but there was, a frontal shift of the target-locked P3, indexed as reactive control, among older adults. We observed an increased target-locked P3 in the no-information paradigm compared with the cue-based and memory-based paradigms in both groups. Task cue facilitated advance preparation and proactive control under the cue-based paradigm in both groups. Age-related decline and difficulty in control processes required for task goal maintenance were apparent among the older adults.